Abstract
Binding of epidermal growth factor (EGF) to its cell surface receptor induces production of H2O2, which serves as an intracellular messenger. We have shown that exogenous H2O2 reversibly inactivates the phosphatidylinositol 4-phosphate [PtdIns(4)P] phosphatase Sac1 (suppressor of actin 1) at the Golgi complex of mammalian cells by oxidizing its catalytic cysteine residue and thereby increases both the amount of Golgi PtdIns(4)P and the rate of protein secretion. Here we investigated the effects of EGF on Sac1 oxidation and PtdIns(4)P abundance at the Golgi in A431 cells. EGF induced a transient increase in Golgi PtdIns(4)P as well as a transient oxidation of Sac1 in a manner dependent on elevation of the intracellular Ca2+ concentration and on H2O2. Oxidation of Sac1 occurred at the Golgi, as revealed with the use of the Golgi-confined Sac1-K2A mutant. Knockdown of Duox enzymes implicated these Ca2+-dependent members of the NADPH oxidase family as the major source of H2O2 for Sac1 oxidation. Expression of a Golgi-targeted H2O2 probe revealed transient EGF-induced H2O2 production at this organelle. Our findings have thus uncovered a previously unrecognized EGF signaling pathway that links intracellular Ca2+ mobilization to events at the Golgi including Duox activation, H2O2 production, Sac1 oxidation, and PtdIns(4)P accumulation.
Original language | English |
---|---|
Pages (from-to) | 40-49 |
Number of pages | 10 |
Journal | Free Radical Biology and Medicine |
Volume | 131 |
DOIs | |
State | Published - 1 Feb 2019 |
Bibliographical note
Funding Information:This study was supported by grants from the National Research Foundation of Korea ( 2018R1D1A1A02049371 , 2012R1A5A1048236 ), from Korea Basic Science Institute ( C38525 ) and from the Ministry of Food and Drug Safety in 2016 ( 16173MFDS009 ) in Korea. The research of TB is supported by the intramural research program of NICHD in USA.
Funding Information:
This study was supported by grants from the National Research Foundation of Korea (2018R1D1A1A02049371, 2012R1A5A1048236), from Korea Basic Science Institute (C38525) and from the Ministry of Food and Drug Safety in 2016 (16173MFDS009) in Korea. The research of TB is supported by the intramural research program of NICHD in USA.
Publisher Copyright:
© 2018 Elsevier Inc.
Keywords
- Cysteine oxidation
- Epidermal growth factor (EGF)
- Golgi complex
- Hydrogen peroxide
- NADPH oxidase
- Phosphatidylinositol 4-phosphate
- Protein tyrosine phosphatase
- Sac1